Kelheimia triangulata, Gründel & Nützel, 2024

Gründel, Joachim & Nützel, Alexander, 2024, Late Jurassic (Upper Kimmeridgian) gastropods from Saal near Kelheim (Germany, Bavaria), Zitteliana 98, pp. 19-72 : 19-72

Kelheimia triangulata sp. nov.

Plate 5: figs 5–11

Etymology.

Latin triangulus – because of the triangular outline of the shell.

Holotype.

SNSB–BSPG 2016 XXI 1749 (Plate 5 : figs 5–7).

Paratypes.

8 specimens, SNSB–BSPG 2016 XXI 1750 –1757.

Type locality and stratum.

Upper Jurassic (Kimmeridgian) reefal limestones from the locality Saal near Kelheim, Lower Bavaria ( Gründel et al. 2015, 2022).

Diagnosis.

As for genus.

Description.

Shell broadly trochiform, conical, slightly coeloconoid; a specimen is 48 mm wide; early whorls slender with distinct sutures; later whorls increase more rapidly producing coeloconoid shell shape; late whorls with straight whorl face, separated by inconspicuous sutures; early whorls with edge above mid-whorl separating oblique ramp and vertical abapical whorl face; several spiral cords present on both whorl portions; approximately 9 bulging, relatively wide axial ribs run from suture to suture forming nodes on edge; as width growth accelerates, edge and axial ribs disappear; straight whorl face of late whorls covered with about 8 spiral cords; cords wider than separating furrows; growth lines straight to weakly prosocyrt, prosocline on whorl face and base; transition from whorl face to base at sharp, angular edge; base anomphalous, slightly convex, covered with wide spiral cords; aperture large with circular lumen and callous inner lip.

Remarks.

Brachytrema (Petersia) sp. sensu Hägele (1997) has bulgy axial ribs on the last whorls and severeal folds inside the aperture (on olumella and outer lip). In Pyrgotrochus cyproea (d’Orbigny) sensu Fischer and Weber (1997) , the whorls are has regularly increasing in width, it has a selenizone, its ornament does not show ontogenetic change, and its spiral cords are narrower. Pleurotomaria berlieri Loriol in Loriol and Girardot (1903) (based on a steinkern) is larger, lacks distinct ornamentation, and its aperture has an edge.

Figures

Plate 5. (1, 2) Creniturbo sp., SNSB – BSPG 2016 XXI 1745, lateral and basal views, width 13 mm. (3, 4) Creniturbo sp., SNSB – BSPG 2016 XXI 1746, collection Lang, (3) detail of base, width 3.2 mm, (4) lateral view, width 3.5 mm. (5–7) Kelheimia triangulata sp. nov., holotype, SNSB – BSPG 2016 XXI 1749, (5, 7) lateral and apical views, width 23 mm, (6) apex in lateral view, height 9 mm. (8–10) Kelheimia triangulata sp. nov., paratype, SNSB – BSPG 2016 XXI 1750, lateral, apical and basal views, width 47 mm. (11) Kelheimia triangulata sp. nov., paratype, SNSB – BSPG 2016 XXI 1751, oblique basal view with aperture, height of aperture 32 mm. (12–15) Vetigastropoda gen. and sp. indet., SNSB – BSPG 2016 XXI 1758, (12, 15) lateral and basal views, width 23 mm, (13) detail of lateral view, width 12 mm, (14) detail of ornament, height 10 mm. (16) Parvulatopsis? sp. 1, SNSB – BSPG 2016 XXI 1759, lateral view, width 12 mm.